Airbrushes are most commonly utilized by artists, graphic designers and photographers to apply paint or other liquid media to drawings, paintings, and photographs. They are most proficient for shading, touching-up photographs, and painting models and ceramics. Typical hand held airbrush are a pencil-like instruments that spray liquid media contained in a reservoir in a controlled manner using compressed air or gas as a propellant. In such commercial airbrush assemblies, the liquid media is generally provided in either a funnel type reservoir or a jar type reservoir.
For example, U.S. Pat. No. 4,161,289 to Rebold (1979) discloses a side mounted funnel type reservoir adapted to mount onto the body of the airbrush via a coupling tube. The liquid contained in the funnel type reservoir is gravity-fed through a coupling tube into the main body of the airbrush where it is atomized by means of compressed air or gas passing through the airbrush. The atomized liquid can then be discharged through the nozzle in the form of a spray.
These funnel type reservoirs have disadvantages:
(a) The liquid media can be easily spilled from the funnel requiring the user to keep the airbrush upright when the funnel type reservoir contains media.
(b) when the user is finished with a particular liquid media, the liquid media must be discarded or transferred from the funnel type reservoir back into its original container or into another suitable container. The funnel type reservoir must then be cleaned before loading it with the next liquid media to be used. This is a cumbersome and costly process for professional artists who rely on producing a quantity of work in an expedient manner.
The airbrush disclosed in U.S. Pat. No. 4,171,097 to Rebold (1979) uses a jar type reservoir that is referred to as a "standard size, commercially available glass jar". The jar type reservoir offers a more proficient method of supplying liquid media for airbrushes as it eliminates the need to maintain the airbrush in an upright position to avoid spilling and therefore can be used at steep angles while airbrushing. The jar type reservoir is attached to the main body of the airbrush either directly by coupling the jar directly onto the main body of the airbrush as shown in FIG. 7 or indirectly by coupling the jar to the main body via a coupling tube provided in the lid of the jar as shown in FIG. 6. In both methods, an air inlet hole is provided to prevent creating a vacuum in the jar. In use, compressed air is provided to draw the liquid media up an aspirating tube by venturi effect to atomize the liquid media into small droplets before being sprayed out the nozzle. Since both the direct and indirect configurations utilize a standard size jar type reservoir opening, the jar used for the liquid media reservoir must also fit the standard opening.
Although the benefits of the jar type reservoir outweigh those of the funnel type reservoir, there are still disadvantages:
(a) Airbrush liquid media is most commonly purchased commercially in small, bottle-like containers. Therefore, the liquid media must first be transferred from its original container to a standard size jar in order for it to be used with an airbrush. The user must then discard the unused liquid media or return it to its original container when finished. The standard size jar must then be cleaned before loading the next liquid media to be used similar to the funnel type reservoir. In addition, each time liquid media is transferred from one container to another, a small amount is wasted. Therefore this method is costly as well as cumbersome.
(b) If the user did not wish to clean the jar when changing liquid media he could purchase and use many jars; (i.e. one jar for each liquid media to be used). This would be costly and troublesome.
(c) The air inlet hole can become clogged by the liquid media splashing against the reservoir opening caused by the motion of the liquid media in the reservoir during airbrushing.
Other methods of supplying liquid media to airbrushes are disclosed in U.S. Pat. Nos. 4,508,271 to Gress (1985) and 4,546,922 to Thometz (1985) both of which offer the user the capability of selecting from multiple supply reservoirs containing different liquid media. Although both methods provide the user with multiple liquid media to choose from while airbrushing, there are disadvantages:
(a) The liquid media selection is limited by the number of supply hoses and/or reservoirs.
(b) The user must transfer the airbrush liquid media from the commercial container in which it is purchased to a supply reservoir before airbrushing. The unused portion of liquid media must be returned to its original container or discarded which results in unnecessary waste and inflated cost. The reservoir must then be cleaned before loading the next liquid media to be used.
(c) Both methods involve meticulous and difficult manufacturing processes which result in higher production costs that are usually passed on to the user.